One creature takes damage for another

[BeefGood]

I'm looking for a spell/ability/feat/magic item that permits one creature to take damage for another. I flipped through the books last night and did not find such a thing, so help would be appreciated.
Context: I'd like to give a player, a halfling rogue, a mechanism to keep his pet/mount mastiff alive in combat. The characters are fighting more powerful monsters now and the mastiff has only 5 hp so he doesn't last very long. If, when the mastiff gets hit, the player could take the damage, then the player would have a means of keeping the mastiff alive, but there would be a cost, so so it would be kind of balanced. In case it's relevant, the mastiff is sometimes a mount, and sometimes a fighting companion (helps the rogue get sneak attack if no other means is available).
Thanks.

[DivisibleByZero]

He's using it as a mount?
Mounted Combatant feat. When an attack is directed at the rider, the feat allows him to direct it at himself instead. It also effectively gives the mount evasion.

[nickl_2000]

He's using it as a mount?
Mounted Combatant feat. When an attack is directed at the rider, the feat allows him to direct it at himself instead. It also effectively gives the mount evasion.

Mounted Combatant only applied when the character is riding the mount though. So, it won't re-direct when he is off the mount. Your best bet would be a homebrew enchanted collar/ring set or something like that

[DivisibleByZero]

Mounted Combatant only applied when the character is riding the mount though. So, it won't re-direct when he is off the mount. Your best bet would be a homebrew enchanted collar/ring set or something like that

Why get off of it? It's medium, and it's just a dog. It still counts as an ally when you're riding it. There's no reason to dismount.
If you want to dismount, and you're worried about the mastiff, just tell him to "sit" and let him wait.

[nickl_2000]

Why get off of it? It's medium, and it's just a dog. It still counts as an ally when you're riding it. There's no reason to dismount.


Because I didn't think about the idea of an ally threatening within the same 5 foot as you. It does fit RAW, so hey why not

[Slipperychicken]

Warding bond does half of it, but it might not be as helpful unless you can stack up some extra hp for your pupper.

I'd suggest also buffing the dog's health with some temp hp, an Aid spell, and the best barding you can afford. Death ward might be overkill depending on how attached you are to it.

Mounted combatant is a no-brainer if you plan on riding it all the time.

A homebrewed magic dog collar could also serve your needs.

[Zejety]

I am pretty sure that there is a precedent for this in some Unearthed Arcana, probably a Paladin Oath.
Maybe it's even in the Oath of the Crown in SCAG?

[Biggstick]

I am pretty sure that there is a precedent for this in some Unearthed Arcana, probably a Paladin Oath.
Maybe it's even in the Oath of the Crown in SCAG?

Yep. OotC's 7th level ability is the capability to use a reaction to take the damage for an ally within 5' of you. You can't reduce the damage in any way though.

To simply give a level 7 ability like this to a Rogue would seem pretty powerful. But if it can be restricted down pretty hard in a way you see fit, or other Players have something of similar power, then I don't see a problem with giving this to said Player in some way shape or form.